1 0 Kinematics PPGuided Notesx

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14 Νοε 2013 (πριν από 4 χρόνια και 6 μήνες)

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Unit 2
-
Kinematics

Kinematics
-
What is it?

Kinematics

________________________________

_____________

is always defined in terms of change in
_______________.

Locations or Positions are defined in terms of some
_________________________.

Many ti
m
e
s we use our
____________________________

to define F/R.

Scalars and Vectors

When discussing kinematics, and truly, all aspects of physics, we will be using two
different types of measurements

Scalar Quantity:

The Price is \$12.00 is a scalar.

Vectors
Quantity:

The price
Increased

by \$12.00 is a Vector.

Vectors

As stated, a vector is a
_____________

(How big or How much) with a
_____________
.

Ofte
n we will
draw vectors as ________________

pointing in the direction of the
vector.

We can add vectors (
_________________
):

Algebraically by placing the vectors
___________________

and then finding
the algebraic sum

or Graphically.

(_________________)

Distance

is a Scalar

_______________

and
_________________

seem very similar, but they actually
have distinct meanings.

Unit 2
-
Kinematics

___________________

is a scalar quantity which refers to how
__________

a body
______________

in going from
_____________________________.

Example:
12 m is a
_______________
…it tells how far.

Displacement is a Vector

____________________

(generally written as….
Δ
x or
Δ
y…..is a
____________

_____________

which refers to the
_________________________________

________________________
________
. Direction can be given in a lot of ways,
by compass
directions (N, S, E, W) or by ___or

___
sign along the

x (
______________
) or y (
_________________
) axis.

Example #1

A student walks 100 m to the East and then walks 300 m to the West.

What is the
student’s total distance traveled?

At the end of her walk, what is her total displacement?

Example #2

A student walks 4 m east, 2 m south, 4 m west, and finally 2 m north.

What is the students total distance? Displacement?

Example #3

A family travels

50 km south on I
-
75 and then gets off on exit 117 and follows a dirt
road 15 km east.

What is the families total distance traveled?

At the end of their trip, what is their total displacement?

Speed & Velocity

Speed

______________________________

Velocity

_____________________________

Calculating Speed

In order to find the average speed or average
___________________

of an
objects velocity
________________________

it has traveled by the
___________

it took to travel that distance.

Speed =
_______/___________ Or _____________

Unit 2
-
Kinematics

Defining and Calculating Velocity

We can look at and
______________
in a couple of ways

Instantaneous velocity

Average velocity
-

Calculating Velocity

Velocity is

It’s important to remember that
__________________

has
_________________!

Practice

What is the velocity of a car that travels 75 km towards Richmond in 5/6 hour
(give answer in km/hr and m/s)

What is the speed of a person who runs 10 km in 1.5 hours (answer in km/hr and
m/s)

Accel
eration

Acceleration
is the measure of how

___________________________________________________________.

Formulas for acceleration (or change in velocity):

More Acceleration

Acceleration is a measure of how
________________________

during a particular
length of time. Remember! Vectors not only tell How Big a Quantity is, but also in
___________________________________________!

So, a body may travel at a constant speed, but
____________________________
,
it is
______________________
________
!!!

Unit 2
-
Kinematics

Centripetal Acceleration

An object moving in a circle is accelerating because

it’s
___________________
is
changing even if it’s
__________________

is remaining constant

Acceleration is a VECTOR

This means that Acceleration has a
______________________(
______________

______________________________________)

It also tells us in what
____________________

that
______________________

takes place.

This is normally done with
______ or _____
signs.

+ means to the
_____________ or _______
____.

-

means to the
_____________ or ___________.

More Acceleration

So by convention, if an object is
____________________
, and the acceleration
(speeding up) is in the same direction as the velocity. This gives the object a
______________
__________________.

If an object is
_____________________
, and the acceleration (slowing down) is in
the opposite direction of the velocity. This gives the object a
_________________
______________________
.

Examples of acceleration

Give some examples of positive acceleration

Give some examples of negative acceleration

Name four controls in a car that can cause an acceleration

1.

2.

3.

4.

Unit 2
-
Kinematics

Calculating acceleration

To find acceleration, we divide the
___________________________

by the
___________
it takes for that change (rate of change of velocity)
.

Acceleration =

Practice Problems

A vehicle initially traveling westward at 35 km/hr and comes to a stop in 15 s. What

is the magnitude and direction of the acceleration of the
vehicle?

A rock is dropped from the top of a cliff and after 10 seconds is traveling 40 m/s.
What is the magnitude and direction of the rock’s acceleration?